/Engine/Source/Runtime/GeometryCore/Public/Util/SparseIndexCollectionTypes.h
Dense variant: returns true unless you have set index to InvalidIndex (eg via SetToInvalid) sparse variant: returns true if index is in map or default index is >= 0 scaleandoffset variant: returns true if default index is >= 0 all return false if index is out-of-bounds
bool Contains ( int Index )